'use strict';
var is_exist_element = function(collection,element){
  var num = []
  for (let i = 0; i < collection.length; i++) {
    if(i%2==0){
      num.push(collection[i])
    }
  }
  var flag = false;
  for (let i = 0; i < num.length; i++) {
    if(num[i]==element){
      flag = true;
      break;
    }
  }
  return flag;
};
module.exports = is_exist_element;
